Getting more internal space for apps - Android

My wife and her mother have two Android cell phones, both with 8 GB internal space.
Just the Android OS takes half that space, leaving very limited space for apps like Facebook, Facebook Messenger, Instagram, Snapchat and Whatsapp.
Installing something else may be a hurdle.
Unfortunately some preinstalled apps and games can't be removed, only deactivated, but still take space.
External memory can't help as we can't install those apps in the SD card.

You can't install the apps on the SD card even though your wife's phone is on Android 6? That's strange. It's been possible to put apps on SD cards since Android 5. Some apps won't run off SD cards because the devs don't want them to, but most apps should.

But running apps off SD isn't ideal. The apps will load very slowly, especially bigger apps like Facebook. Just get your wife a good phone with more internal storage (at least 32GB).

If the issue isn't the SD card and the app itself--if the app itself refuses to load from the SD card, then you'll either have to make some space, or get a new phone with more internal storage. You can get good phones for a pretty cheap price these days, or you can buy an old flagship for very little here on RFD.

You could even try flashing a custom ROM onto the phone to see if the storage used by the system OS is reduced. But this involves voiding your warranty, rooting, unlocking the bootloader, and so on. A lot of hassle for a phone with just 8GB internal storage.

What phones are you trying to create space for, and which apps? If I knew the specific apps, I could try testing if they run off SD myself, since I have a Class 10 card.

The only solution is to root the phones. If you do that, you can delete very pre-installed app they don't use, and there are root apps that will help you move "unmovable" apps to the SD card. You may be able to move a few apps to the system partition too, if there's sufficient space there.

The only solution is to root the phones. If you do that, you can delete very pre-installed app they don't use, and there are root apps that will help you move "unmovable" apps to the SD card. You may be able to move a few apps to the system partition too, if there's sufficient space there.

I don't think the space saved by deleting "system apps" helps with improving user storage area. The /system partition is separate and distinct from the /data partition. All those apps that can only be disabled or updates uninstalled are stored in the system partition. Deleting them does nothing to make more usable space in the /data partition. Having said that, all updates to apps installed in /system are stored in the /data partition. So, there is savings to be had by disabling these system apps. I hate to say it, but the only solution is to replace the phone or do adoptable storage for android 6. Adoptable storage "stitches" the external sd storage into the internal storage. It is not the panacea for storage issues.

I get by with 8 GB. I use the adoptable storage with Marshmallow and move as many apps as I can. Also I delete any apps I don't really need and just use my computer or tablet. It is important to clear the cache frequently because it will use up space so that you can't update apps.

I will give the adoptable storage a try. Haven't thought of it.
We're in a tight budget and can't get a 16 GB phone at this moment, so we'll have to work with what we have.
I've tried deleting some pre-installed games and apps but they don't take much space. Facebook alone takes around 260 MB.
I read apps like Apps2SD can help determine which apps can be moved to an external card, but we need space to install that app :p
Cache cleaning is also a good tip.

I'm only familiar with older versions of Android, but it used to be that when you updated a System app, the old version doesn't get overwritten (ie. original version sits in the System partition, while the updated version sits in the User partition).

Rooting your phone would allow you to move the updated version to the System partition, overwriting the old/original one, thus leaving you with more space. Play Store and Google Services aren't exactly small.

As always, I recommend backing up apps before updating them, since new versions can sometimes suck.

I tried the adoptable storage last night. So far so good!!!
I moved Facebook, Facebook Messenger, and Snapchat.
I believe they run a bit slower. How slower? I don't know. I will hear from my wife complaining if so.
But very cool feature!!!
Not sure if I can do it with her mom's cell phone. Her OS is not 6.

I tried the adoptable storage last night. So far so good!!!
I moved Facebook, Facebook Messenger, and Snapchat.
I believe they run a bit slower. How slower? I don't know. I will hear from my wife complaining if so.
But very cool feature!!!
Not sure if I can do it with her mom's cell phone. Her OS is not 6.

There's an Xposed module out there that lets you use adoptable storage with Android 5 (Lollipop).

But you'll have to root the phone and then flash Xposed. But the phone may not be rootable or support Xposed. And who knows if it'll work with that particular phone model.

Here's some advice: stop using the Facebook app. It's an unoptimized battery hog and is known to slow down phones. Use the mobile Facebook website instead (i.e. Facebook in your phone's browser). The apps run slower because they're probably on a non-Class 10 SD card. But even on a Class 10 SD, Facebook does run quite slow from what I've noticed. That's the problem with adoptable storage. You should really only keep files on SD cards, not apps.